The LM397 is a single voltage comparator with an inputcommon mode that includes ground. The LM397 is designedto operate from a single 5V to 30V power supply or a splitpower supply. Its low supply current is virtually independentof the magnitude of the supply voltage.The LM397 features an open collector output stage. Thisallows the connection of an external resistor at the output.The output can directly interface with TTL, CMOS and otherlogic levels, by tying the resistor to different voltage levels(level translator).